Tubular molding core for pipes



T. E. MURRAY.

TUBULAR MOLDING CORE FUR PIPES.

APPLICATION FILED )LILY 7, i921.

Patented Feb. 14

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351g SMOWWM lar to i UNITED ASTATES PATENT clerics.

THOMAS E. MURRAY, Y0F BROOKLYN, NEW YORK.,

TUBULAR MOLDING COYRE FOR PIPES.

applicationA inea my 7,

To all whom 'it may concern.

Be it known that I, THoMAsE. MURRAY, a citizen of the UnitedStates," residing at Brooklyn, in the county of Kings and State of New York, have invented'a certaink new and useful Improvement in Tubular Molding Cores for Pipes, of which the following is a specification.

l The inventionis a tubular molding core for pipes of plastic cement or the like, formed wholly of bibulous paper or like bibulous fiexible material.

In the accompanying drawing-V Fig. 1 shows my core formed from a spiral strip of paper upon a Vsuitable mandrel. Fig. 2 is a longitudinal and Fig. 3 is a cross section (on the line` 3, 3 of Fig. Q)v of said core with the pipe molded thereon. Fig. 4l illustrates the mode of removing the core after the cement has sufficiently set. Fig. 5 is a longitudinal section of the finished ipe Fig. 6 is a sectional view simi- IFig. 2, the core here being madeof a plurality of spirals Wound one upon the other and in opposite directions. Fig. 7 is a sectional view, also similar to Fig. 2, in which the core is made of two spirals, the outer one being of bibulous and the inner one of'non-bibulous paper.

Similar letters of reference indicate like parts.

The core upon which the pipe is molded is to be preferably of bibulouspaper having overlapping edges united by a paste soluble in Water. I preferably form said core A in spiral form bywinding the same upon any suitable mandrel, as B, with its turns overlapping, as shown at C, and united by the paste, so that When removed from the mandrel it is a stifl tube. Upon this tube the cement D or other plastic material which is to form the pipe is directly molded, as shown in Fig. 2. When the core is thus enclosed in the plastic cement, it absorbs WaterV therefrom. which softens the fastening paste, so that the core may be unwound, as illustrated in Fig. 4t, by the hand of the operator grasping one end of the spiral strip which may then easily be Withdrawn from the molded pipe. This Withdrawal may be done after all the applied cement'has hardened; but I find that with suitably absorptive paper it may be accomplished usually after the cement mass has set for a sufficient distance-for example, as indicated at E, Fig. winwardly from its inner surface to en .specificationofretters Patent. Patented Feb, 14,'1922 192,1. seria; No. 482,913. y

able said` set portion'to support the still more or less plastic outer Iportion F,fand s0 prevent deforma-tion l,ofthe mass after Athe core has been removed. vIn either case, the core not only serves as a support Whereon the cement is molded, but also by its absorption of the moisture first from the ad- ]acent inner surface of the cement Vdetermines the initial hardening of that part of the molded mass.

K Instead of making the coreof a single strip of paper, I may4 make it in layers H, I, J of superposed spirally Wound strips, which may have their turns in alternately opposite directions, as shown in Fig. (i, in

which case, after the softeningof the, paste,

is of bibulous paper and the inner spiral K or spirals of non-bibulous paper, the latter Y then serving to strengthen and support the structure. In this case, the sheath G will be removed after the paste `has become rsoftened, in the manner already described, after which the inner ones can easily be Withl drawn from the pipe.

Attention is called Vto the fact that this core is made of nothing but flexible bibulous material-preferably, as I have said,

paper-in tubular form, and is, therefore,

free from any internal supports of Wood or metal and is not held distended by air` pressure or any other extraneous means. It is, therefore, very` cheaply produced. lThe mode of its removal describedby manually unwinding after the paste is softenedensures that its complete removaly from the pipev Without the aid of any special appliances for that purpose, and because of such complete removal there is nothing left in the pipe to become Washed away by water traversing the pipe or torn therefrom by the drawing of electric conductors through itand, therefore, all danger of fragments of paper being accumulated in bends, el-A the bore, Which will support the rest of the mass even if it be quite soft; so that it is not necessary to leave the core in plaeeuntil the Whole Wall of the pipe hashardened before proceeding to make another section of the pipe in prolongation of the one already made. i I v I claim: l 1. A tubular molding core for cement pipes formed of bibulous material having overlapping edges united by a. paste soluble in water. v

2. A tubular molding core, as in claim l,

`\pipes formed of a plurality of strips of bibulous materal'spirally Wound in successive layers, and each strip having overlapping edges united by a paste soluble in Water.'

In testimony whereof I havel aixed my signature in presence of two Witnesses.

THOMAS E. MURRAY. Witnesses:

GERTRUDE T. Ponrn, Mar T. MoGnmr.` 

